Holding and supporting device for printing or print-receiving elements and the like



Nov. 4, 1930. w c. HUEBNER L789677 HOLDING AND SUPIORTING DEVICE FORPRINTING OR PRINT RECEIVING ELEMENTS AND THE LIKE Filed Oct. lO, 1924 5Sheets-Sheet l 76 T/ I S e 4/ E@ C @Y j@ l\ f/ H l e l Z/ @i E u 21- 4Z1;@ 45

ff De@ 1, n, wf mi f' @W @"e Z/ 4 c I 46/ .Elm Z /l i {Cmq l yf .iL-A l4/ nlm.

A rfa/@via NGV- 4 i930 w. c. HUEENER HOLDING AND SUPPORTING DEVICE FORPRINTING OR PRINT RECEIVING ELEMENTS AND THE LIKE Filed oct. 1o, 1924NGV., 4f, IQB. W. Q HUEBNER Ij?? HOLDING AND SUPPORTING DEVICE FORPRINTING OR PRINT RECEIVING ELEMENTS AND THE LIKE Filed Oct. lO, 1924 5Sheets-Sheet 5 @y /a a@ A 77E/@VE K5.

Nov., 4, 1930. W. c.

HOLDING AND SUPP HUEBNER ORTING DEVICE FOR PRINTING OR PRINT RECEIVINGELEMENTS AND THE LIKE Filed Oct. lO 1924 5 Sheets-Sheet 4 iii.

lillhmw-..

vid@

Aff fea/iw W. c. HUEBNER Filed Oct. lO 1924 OR PRINT RECEIVING ELENENTSAND THE LIKE HOLDING AND SUPPORTING DEVCE FOR PRINTING Nov. 4, 1930.

Patented Nov. 4, 1930 UNITED STATES PATENT OFI-icel HOLDING .ANDSUPPORTING, DEVICE FOR PRINTING OR PRINT-RECEIVING ELEMENTS l l AND THELIKE Application led October 10, 1924. Serial No. 742,919.

This invention relates to holding and supporting means or devices uponwhich printing or print receiving elements are mounted and supported toadapt them for use in photo-composing and other mechanical photographicprinting apparatus. The invention relates particularly to a portableholder or support on which flexible sheets, films or the likeare adaptedto be mounted and drawn taut and having means whereby an image on suchsheet may be accurately positioned in predetermined location andregistered as to size by the stretching of the sheet or film on theholder or frame. The holder is particularly adapted for use inconnection with the process outlined in my copending application forLetters Patent, entitled Process of preparing and registering printingsheets or lilms, filed July 31, 1924, Serial No. 729,277.

In the production of the printing plates', for instance for poster work,the use of glass plates or lithographic stones is very expensive, andfurther, in the case of large posters the `iob must be done in sections,that is, a number of separate plates are used, each bearing a differentportion of the final picture, and these portions must not only registeraccurately with the original image, or with a layout sheet or the like,but the abutting edges of the sections must register accurately witheach other. s

As is well known, there are many disadvantages in the userof glass forthis purpose. The surfaces of the glass plates are sometimes not flatbut wavy, and at other times the opposite faces ofthe plates are notparallel; again there are variations in the thickness of a series ofglass plates for one color job, or for the different sections of a largesubject. rlhese imperfections in the' glass add to the'difhculties inregistration of the images on the press plates, and also prevent perfectcontact between the glass plates and l the press plates orprint-receiving surfaces.

' Further, it is diiiicult to handle large plates of glass in quantityproduction during the various operations or the exposure and developmentand the other finishing operations; many plates are broken in handlingthem, and due to uneven pressure as a result of the uneven surfaces orvarying thickness before mentioned. Finally, the expense attendant uponthe use of glass plates is very great, as large quantities of glass areaccumulated, resulting in a large unproductive investment, and expenseand inconvenience in the storage of the glass which requiresconsiderable space and appliances for the handling and the protection ofthe stock.

Devices heretofore used for supporting the glass or other rigid printingor print receiving elements have included a plate holder having devicesfor adjustably positioning and securing the plate thereon, an asupporting member on which said holder is removably secured, said memberbeing adapted to be placed in the printing apparatus to enable theprinting element to be placed in predetermined position for use on theprinting apparatus so as to produce printing press plates therefrom byeither contact or projection methods. The supporting member with theholder in place thereon was adapted to be secured on the printingapparatusin predetermined position, as by inter-engaging parts on themember and the machine, said member parts also being adapted tocooperate with parts on an image positioning or registering apparatus ordevice for positioning the images on the plate in accordance witharequired layout sheet or other data so that by providing a plurality ofthe supporting/members and holders, one printing element could bearranged on a holder on one supporting member, and the whole placed onthe registering device to position the printing element, while anothersimilar element previously registered in a like manner, was being usedin the print- -in a aratus. These devices however have been relativelyexpensive for the reason that lin addition to the necessity of providingone or more plate holders for each size of plate used, a plurality ofsupporting members having different sized openings are required eachadapted to be used with only one size of holder. rlhese supports, inaddition to their expense, are relatively heavy and cumbersome and aredifficult to handle, and their use consumes much time and entails theuse of special equipment to move them about from the image positioningonregistering device to the printing apparatus, or elsewhere, and thefrequent changing of the holders on the apparatus prevents theexpeditious production of work.

It has long been recognized that flexible photographic films, or sheets,of sensitized paper, fabric or other suitable flexible, transparent orother material-are desirable from various standpoints for use in theplace of the usual expensive glass plates before mentioned, especiallyin the production of the elatively large photographicimages required incommercial photo-lithography and other printing arts, for use asprinting elements in the production of photo-printing press plates. Upto the present time, however, no satisfactory means or devices have beenproduced whereby such films or sheets can be positioned as required andheld firmly and stretched smoothly without wrinkles or undulations sothat the image bearing surface will lie in a true plane. An uneven filmor sheet results in the production of a hazy and misregistered image,due to improper focus in the case of projection apparatus, as parts ofthe sensitized surface would be out of the focal plane'of the projectedimage, while in contact work it is impossible to obtain perfect contactand perfect impressions over the entire area.

Furthermore, the use of such films or sheets for multicolor or otherwork requiring a number of images that must all register exactly as todimensions and position one with another and with the original or with amaster copy, layout or other registering device or guide,

has not heretofore been considered feasible owing to the characteristictendency of the materials of which the films or sheets were made toshrink and expand or otherwise change condition either generally orlocally, which would cause misregister of the prints made from thesheets, hence nullifying the otherwise desirable qualities of such filmsor sheets.

Objects of the invention are to provide Aa holder of improvedlconstruct-ion including a frame provided with means for securingvaphotographic film or other flexible sensitized sheet, or an imagebearing sheet by its edges on the frame and whereby it may be stretchedor drawn taut and smooth over the frame opening; also to provide aholder having means whereby a flexible image bearing film or sheet maybe arranged on the holder in definite relation to an image bearing glassplate orv other rigid member secured on the frame beneath and in contactwith the sheet, and whereby its image may be registered both as to sizeand position with said underlying image, or so that the image on thesheet may be accurately brought to predetermined position by the use ofsuitable ima-ge positioning means or devices by manipulating thesecuring and stretching means or devices.

Another object is to construct a portable holder of this sort having aplurality of sheet gripping and stretching devices adjustably mounted onthe holder frame and which are capable of independent adjustmentrelatively to said frame to permit variable tension to be applied todifferent areas of the sheet or lm, thereby permitting the same to bestretched, either locally or generally, as desired; also to provide theframe or holder with adjustable means whereby a glass or other rigidplate may be adjustably secured in or over the opening of the frame soas to act as a back support for the lm or sheet when said sheet bears an.image from which it is desired to take an impression or reproduction,or to permit a glass or the like plate bearing an image to be adjustedto and secured in predetermined position so that a -fiexible film orsheet bearing an image may be arranged above the plate and stretched andadjusted to position its image in predetermined relation to the image onthe glass plate.

Still another object is to provide a support for the plate holdermentioned, whereby av relatively large number of the holders of the sameor of different sizes, may be used without the necessity of providing aseparate complete support for each sizeof plate holder, and so that theusual large and expensive glass support for the printing orotherfelement may be dispensed with also to construct said .plate holdersupport so that the image or images on the flexible film or sheet, -oron the rigid glass plates on the holders can be placed in predeterminedregister with a master or zero position which has been located orpreregistered on a photographic printing apparatus, so that after theimage onvthe sheet or plate has been positioned on the holder, theholder with the sheet or plate thereon, or both a sheetand a platethereon, can be removed from the image positioning device and placed incorresponding position on the printing apparatus. with the assurancethat the image or images will coincide or register with said masterposition. A further object is to construct such a support of two membershaving means whereby, when one of the members is placed on the othermember it may be adjusted relatively thereto to occupy a definitepredetermined location thereon and will be removably secured thereto soas to form a single portable unit; also to so con-` struct such unitsthat one of them may be arranged on a photographic printing or the likeapparatus, and another like unit may be arranged on an image positioningor registering apparatus or device, so that any number of the holdersmay be placed on one or the other unit and, when so placed, will alwaysoccupy the 'same relative position on either unit, thusenabling imagebearing films, sheets or plates to be accurately registered inpredetermined position on the-image positioning device, and then byremoving the holders only and placing them on the other unit on theprinting apparatus the image on the sheet or plate will be in exactlythe same relative', predetermined location.

vide holders for the purpose described with improved means for enablingsaid holders to be used on photographic printing apparatus whereinsuction is used for the purpose of withdrawing air from between thesurface of the image bearing sheet or the plate on the holder and theprint receiving surface onn which it is desired to produce an impressionof said image, for the purpose of'obtaining close contact between saidsurfaces; and also to improveeportable holders for photographic printingor other'A like elements, and to improve the supporting means or devicesfor such holders in the other respects hereinafter specified andclaimed.

In the accompanying drawings:

,Fig 1 is a face view of a holder embod ing my invention on whichflexible sheets, lms or the like are adapted to be stretchedand secured,and glass or other rigid plates secured so that images thereon may bepositioned on the holder in predetermined position.

Fig. 2 is a transverse sectional elevation thereof on an enlarged scaleon line 2-2, Fig. 1, showing one of the sheet gripping de- 3.; vices orclips thereof. i

FiF ig. 3 is an end view of the clip shown in g. j

Fig. 4. is a sectional plan view of the clip.

.f Fig. 5 isa side view of one of the pressure devices for the clips.

1,Fig 6 is a sectional plan view of one of tie holder.

Fig. 7 is a cross Vsection thereof on line ,7-7, Fig. 6.

Fig. 8 is a plan or face View showing a holder as illustrated in Fig. 1arranged on its supportand positioned on an image positioning device.

Fig. 9 is a sectional elevation of the holder and its support on line9-f9, Fig. 8, and ,on an enlarged scale. f

Fig. 10 is an elevation showing the holder on its support arranged onapart of a photographic printing apparatus.

Figs. 11 and 12 are face views of the'pri.-

mary and secondary members respectively of the holder support. s G0 Fig.13 is a face view of a holder of slightly modified form, showing aportion of la. flexible sheet secured thereon. i

Fig. 14 is a transverse section thereof on line 1li-14 Fig. 13.

Fig. 15 is afragmentary face-view, on an plate securing devices or clipsof the enlarged scale ofl a portion of the holder shown in Fig. 13.

Fig. 16 is a transverse section thereof on line 16-16 Fig. 15. Y d Figs.17 and 18 are perspective views of the two jaw members of the sheetgripping device or clip shown in Figs. 13 and 16. A further object ofthe invention is to pro- Fig. 19 is a sectional elevation showing aholder of the construction shown in Fig. 13 arranged in relation to aprint receiving surface for making a contact print from an image on theflexible sheet.

In the embodiment `of the invention shown in Figs. 1-.12, a holder isprovided having means whereby a rigid glass or other transparent plate,or photographic image bearing element, and also a flexible image bearingor other' photographic film or sheet may both be secured on the holder,the rigid plate being adjustably positioned on the holder and theflexible film or sheet bearing on the face thereof and adapted to bestretched taut and smooth, and whereby an image on a flexible sheet maybe registered, both as to size and position on the holder. Said holdercomprises a frame A, a plurality of adjustable securing devices B forthe glass or rigid plate D, and a plurality of gripping devices or clipsC adapted to grip the edge portions of a fiexible sheet or film E so asto stretch or draw the same taut over and in contact with the glassplate.` .The frame is preferably made rectangular with a rectangularcentral opening or aperture l2, the dimensions of which are somewhatless than those of the plate or film to be used on the holder.v 'v Theframe A. is formed with a flange or ledge 13 on one face, as its upperface and surrounding said aperture. The ledge is preferably providedwith a rubber orother gasket 14 adapted to form a yielding support onwhich the plate D may rest so as to be supported adjacent its edgesacross the aperture 12. rlhe edges of the plate are preferably beveledas shown and form with the top surface a corner d extending around theplate adjacent the edges of the opening 12, and the plate securingdevices B `engage the beveled edges and hold the plate firmly down linplace on the gasket 14. The plate securing devices B are secured on theframe at intervals around the aperture 12, the number of devicesdepending on the size of the holder. Each device B includes a movablejaw or member 15 slidably adjustable `in a swivelled block 16,

and having a beveled edge adapted to engage,

the beveled edge of the plate. As shown the jaw has a dove-tailed shank18 engaging in a guideway in the block 16, andan adjusting screw 19,journaled in the block, engages in a threaded hole in the shank 18, sothat by turning the screw the jawcan be moved to- Ward and from theplate D. The swivel block 16 has segmental circular edges .engagingcomplementary curved faces on plates 20 removably secured on the frame.The plates 2O and block 16 are flush, and a retaining plate 21 securedby screws 22 which pass through the plate 21 and plates 20g into theframe- A maintains the block in place. In addition to the transverseadjustment of the jaws 1 5 in the swivel block 1.6 the latter can turnto a limited extent on the frame A, thus permitting the beveled edges ofthe jaws to be automatically alined with and squarely engage the bevelededges of the plate D, even should the plate for any reason be requiredto be positioned in a slightly angular relation' to the aperture 12.

The securing and stretching devices C for the iexible film or sheet Eare adjustably mounted on the frame A in spaced relation, preferablybetween, or alternating with the device B, and are adapted to grip theedge portions ofthe' sheet so that when the sheet is placed over theplate D and its edges secured inthe devices C, the sheet can bestretched taut and smooth over the plate D by adjusting said devices,which draw the edge portions of the sheet down over the corners d of theplate. Each cli C, see Figs. 1-5 and 9, includes two mem ers or plates25, 26 having gripping jaws 27,28 respectively. The memers are pivotallyconnected, as by a hinge pin 29, to permit one of the jaws 28 to move toand from the other jaw 27. The jaws 27, 28 are preferably provided withcomplev mentary corrugations 32 extending parallel lbe forced into thegroove and held firmly.

rlhe member 25 has a Hat bottom face adapted to bear and have a limitedsliding movevment on the face of the frame 'A. IThese movements arepermitted by means of fixed retaining members 34, see Figs. 3 and/4, apair of which are provided for each gripping device. The retainers 34comprise blocks secured to the frame A by screws or the like 35 andhaving lateral extensions 36 adapted to overhang and engage lugs 37extending laterally from the ends of the member 25. The retainers permitthe member 25 to have considerable movement toward and from the frameaperture 12 and also a limited sidewise movement or play. The clips Care adjustedpreferably by screws 40 swivelled in slots 42 in stationarybearings 41- secured on the frame A f'outwardly' beyond the clips C,-each screw engaging in a threaded hole in the lower member 25 of anadjacent clip C, so that'vby turning thescrew the clip can 'justedlaterally to a slight degree, so that when the clips at the ends, forinstance of the sheet are adjustedthe clips at the sides ,vices C.

may move with the film during such adjustment. The movable jaw, of eachclip is actuated preferably by one or more levers 45, see

Figs. 2, 3 and 5, each having a cam face 46 engaging a complementary camface formed on the clip member 25. ach lever is further provided with aflat top face 49 disposed beneath and engagingthe outer end of themovable aw member 26 and with a pivot stud 50 seated in a hole in member25. By turningthe lever its cam face 46 will ride on the stationary camface and the flat face 49 will move up or down, depending on thedirection of orotation of the lever, and so raise the outer end of themember 26 and force the aw 28 towards the jaw 27, or allow said outerend, which is preferably weighted, to vdrop and swing the jaw 28 awayfrom the jaw 27 to release the edge of the lm. In the constructionshown, a pair of the levers 45, one right hand, and one left hand, isprovided at opposite ends of each clip C. The weighted ends are inclinedwith reference to the face of the frame A and are disposed below or backof the outer face of the glass plate D, so that 5 when the clips aremanipulated to tighten the sheet E, the edge portions of the sheet willbe drawn down against the corners d of the plate D, and the sheet may bedrawn taut and smooth over and down upon the surface of the plate, andas each gripping device is independently adjustable, they can bemanipulated to apply eater or lesstension to -dierent portions ofrthesheet as may be required to effect the desired result.

While the described construction produces a practical and desirableholder, other constructions adapted for the purpose may nbe used. Forinstance, in Figs. 13-19, a holder is shown comprising a frame A',having a central aperture 12a and aplurality of film gripping andstretching devices C which are of different construction from thatpreviously described. In this holder, instead of `providing arigid glassor other plate on which the flhn E is stretched and supported, the frameA is provided with a ledge 53 projecting upwardly around the edges ofthe opening 12 and a yielding strip 54 is secured around the top edge ofthe ledge to form a compressible elevated rim on which the edge portionsof the sheet E are adapted to bear directly, and over which the sheetmaybe stretched taut and smooth over the opening 12a by means of thegripping de- The clips C are arranged in spaced relation on the frame Aand each device includes a pair of gripping members 55, 56 haring jaws57, 58 respectively. The rear edge of the upper member 56 is adaptedlll) to bear on a shoulder 59 of the lower member 55, while the jaw 58is adapted to be forced towards the jaw 57 to grip the edges e of thefilm or sheet by means of one or more levers 61 pivoted at 62 on lugs orears extending upwardly from the member 55, and having eccentricportions 63 adapted, when the levers are swung downwardly, to

, depress the member 56 against the action of a leaf spring 64therebeneath. When the levers are raised as shown in Fig. 16 the jaw 58is permitted to move away from the jaw 57 and release the film or permitthe film to be inserted in the clip. These clips C are releasablyretained on the frame A by retainers 65, and are adjusted by screws 66working in threaded holes 67 in the lugs 67a on member 55 and retainedfrom endwise movement in slots in fixed blocks or strips 68 on theframe, as in the first construction.

Both forms of holders described are adapt` ed and intended to be usedfor mounting a flexible photographic transparent sheet or film thereonand stretching the same taut and smooth over the frame opening and maybe advantageously used in carrying out the process outlined in saidapplication for Letters Patent Serial No. 729,277. The first holderdescribed, being provided with the plate securing devices B, is alsoadapted to support a glass or other rigid transparent member, whereby inaddition to the use of a glass plate to support the film as a printingelement, either by contact or projection methods, a glass plate havingan image thereon may be used, so that an image on a flexible film orsheet may be stretched and registered with relation to an image on theglass plate beneath, the image of which has first been accuratelypositioned by means of an image positioning device. By this arrangement,an image on the film or sheet may be positioned alongside or in definitepredetermined relation to a different image on the glass plate so thatthe two images may be simultaneously exposed and a Combination imageprinted or projected from the` two elements. This construction is also jadapted for contact printing in apparatus requiring a rigid back supportfor preventing the fiexible film or sheet from flexing or giving duringthe printing.

ln the second construct-ion the holder is adapted to support theflexible film or sheet directly on the ledge 53, so that the film, ifbearing an image, may be stretched and the image positioned and broughtto size according to any predetermined layout or other image by the useof an image positioning or registering device. This construction alsomakes it possible to mount a sensitized flexible sheet or photographicfilm on the holder so that the same is taut and smooth without wrinklesor undulations, thus providing a holder which wifi. enable iightsensitive sheets or films to be successfully used in a camera, toreceive a projected image, as the sensitive surface will lie perfectlyfiat in the plane of the projected image. In addition, a rigid glass orother transparent image bearing plate D may be arranged beneath the filmby the use of quoins 69, Fig. 14, or other suitable securing means, andan image on the film registered therewith as to size after which theplate may be removed from the back by loosening the quoins, so that theholder may be used in a camera or photographic printing apparatus andother images of like or different size made from the image on the filmin predetermined like positions relatively to a master image orpreregistered image position. In both the holders A, A the clips B, Cand C', Vand other parts of the holders are arranged below, or back ofthe image bearing or other surface, or at least do not project forwardlybeyond the surface, so that when this surface is brought into contactwith a larger sensitized or other surface, the latter surface will notbe injured or perfect contact prevented between the surfaces byprojecting parts on the holders, see Fig. 19.

A portable support is provided, in accordance with the invention,whereon the holders of either construction described may be mounted orsupported so as to occupy a definite predetermined position either on aphotographic printing apparatus or on an image positioning device or thelike. Said support preferably comprises two members, a pri-. mary member71 and a secondary member 72, both of which are in the form of recvtangular plates having central apertures 7 3, 74 respectively. Thesecondary member is provided with suitable means whereby a holder A or Amay be placed thereon in a predetermined position, as by means of dowelsor studs 75 on the face of the member which fit snugly in holes or seats76 in the back of the holder, and be there removably secured, as bymeans of fingers or latches 77 pivoted on the member 72 and adapted 'toswing into recesses 78 in the side edges of the holder. The primarymember 71 is provided with adjustable securing devices 79 cooperatingwith parts on the secondary member 72 for detachably securing saidmember on the face of the member 71 and eecting a limited adjustment ofthe member 72 relatively to the other member. For this purpose'notcheshaving beveled faces 80, sce Figs. 9 and 12, are formed on the edges ofthe secondary member, which are adapted to be engaged by Aadjustablejaws'81 on the primary member 71. rfhese jaws 81, see Figs. 8, 10 andi1, are slidably arranged adjacent the edges of the member 71 so as tomove in and out in gnideways 82 on the member 71. y Each jaw is moved byan adjusting screw 8f3 sii/iveiied plate 84 izo and having a. threadedend engaging in a threaded hole in the jaw 81. The free ends of the jawsare bevelled and adapted to engage the beveled faces and hold themember72 firmly on the face of member 71. 1n the case of the holder Athese devices 79 not only act as securing means for the member 72 butalso enable an vexact predetermined registration of images onY thesheets or'lms on the holder to be had. For example, when an image onsucha sheet has been registered as to size by visual registration withan image on a plate secured by the quoins as described, this image maybe still unregistered as to predetermined position, as the plate canonly be approximately positioned in the frame aperture. When thereforethe support 71 with the holder A and stretched lm or .sheet thereon isplaced on the printing apparatus and it is found that the image is notexactly in predetermined position, the devices 79 may be manipulated tomove the member 72 relatively to the member l71, over the face of thatmember until the image has been brought to its exact predeterminedlocation.

The support 71--72 is further provided with suitable means for removablysecuring it in predetermined position on either a printing apparatus oran image positioning device. Preferably the member 71 is formed withholes 86 adjacent its opposite ends or upper and lower edges adapted toreceive dowel"pins or locking screws 87 while the photographic printingapparatus, a portion of which is shown in Fig. 10, may haveval pluralityof accurately spaced holes 88 formed in yupper and lower cross bars 89on which the support 71-72 is to be placed. The screws 87 are adapted toengage in opposite selected holes, and when screwed tight, securely holdthe support in the desired position. The holes 88 are arrangedat equaldistances apart, preferably in two directions from a central or baseline position, indicated by the dot and dash line -w. Holes`90 similarto the holes 88 are also arranged at the opposite side edges of themember 71 on a horizontal center line 'J-y so that the support 71-72 maybe turned at right angles and secured to the bars 89 as before.

One form of a suitable image positioning` device is shown in Fig. 8.This device is constructed and operates as disclosed in Letters Patent1,452,078 granted to me April 17, 1923. The device is provided with astand or table 92 on which the support 71-72 is adapted to be supported,and a pair of holes 93, corresponding in position to the holes 88 on theprinting apparatus, is adapted to receive the screws or pins 87, thusenabling the holder to be positioned in exactly corresponding positionson the two machines. VThe'images or subjects on the sheets E, E orplates l), D can be -accurately -positioned according tothepredetermined location therefor by swinging the registering frame 94over in front ofthe holder A or A on the stand and adjusting the clips'Band C until the image or images is or are in correct position asdetermined by the reticules or sighting devices 95, which are movablealong lines corresponding. to position lines and y-y. Registering meansof -various other constructions could also be r used for accuratelyplacing the images in predetermined positions.

The construction of the holder support in two parts 71, 72 enables amultiplicity of different sized holders A or A to be used while onlyrequiring two of the primary members 71 and a small number of secondarymembers 72 for use with a photographic printing 'machine and a separateimage positioning device, for the reason that the different secondarymembers, while having uniform outer dimensions can be formed withdifferent sizes of openings 74 and each of these secondary members canaccommodate several di'iierent sizes of holders as any holder of a sizesuch that the dowels 7 5 can be located on its rear face to registerwith the complementary dowel holes, can-be secured on the same secondarymember as' long as its aperture is 95 equal to or less than the aperture74 of that particular secondary member. By this arrangement a greatsaving in cost of equipment results, and in addition, the holdersdescribed enables the use of paper, o r other flexible films or sheetsin the place of'glass in the preparation of press plates and results instill further reducing operating costs to a marked degree. e

The provision of the rubber or resilient ,gaskets 14 around-the aperture12 of frame lA, together With a similar gasket 98 on a as for instancethe sheet metal press plate shown at 100, Fig. 19. The press plate 100 lextends beyond the edges of the sheet E and is engaged by the gasket 98,thus forming a sealed vacuum chamber 101 around the sheet and itssecuring devices. A suitable nipple or connection 102 is provided forattaching a suction hose or the like to the holder frame A, A towithdraw the air' from the chamber 101'and from between the contactingsurfaces' of sheet E and plate 100. M

I claim as my invention:

`-1. A holder for a flexible photographic sheet or film comprising aportable frame having an opening for the passage of light, a support onwhich said frame is removably secured, a plurality of sheet gripping andlill)- tightening devices ^for said sheet movably mounted on said traineat the several sides of said opening to move independently toward andfrom the opening in a plane parallel with that of said sheet and eachhaving means for independent attachment to thesheet, adjusting means forsaid devices adapted to bodily move and hold said devices independentlyof each other relatively to said frame whereby said devices can be movedto ,and held at different distance-s from said openings so as to applyvarying tension to different portions of the several edges of said sheetto draw it taut and smooth over said frame opening.

2. A portable holder for a iiexible image bearing sheet or filmcomprising a frame having an opening for the passage of light, aplurality of sheet securing and tightening devices for said sheetmovably mounted on said frame at each of the several sides of saidopening to move bodily toward and from the opening in a plane parallelwith that of said sheet and each having means for attaching the sheetthereto, independent adjusting means for each of saiddevices, wherebyeach device may be separately adjusted so that variable tension may beapplied to said sheet at f different portions of its several edges asrequired to draw said sheet taut and. smooth over said frame opening,and means carried by said holder arranged to bear against the undersideof and hold said tensioned sheet so that said securing devices andadjusting means do not project beyond the plane ofthe outer surface ofsaid sheet.

3.A portable holder for a flexible image bearing sheet or filmcomprising a frame having an opening, a plurality of sheet gripping andstretching devices slidably mounted on said frame at the sides of saidopeningY to move independently both laterally and toward and from saidopening, and means for independently adjusting said devices to stretchsaid sheet evenly over said frame opening, each of said devicescomprising a pair of members having jaws adapted to grip an edge of thesheet, and a locking lever having a cam portion adapted to engage one ofsaid members to force and hold its jaw portion into gripping relationwith the other jaw.

4. A portable holder for a flexible sheet or film comprising a framehaving an opening, a plurality of sheet gripping and stretching devicesmovablymounted on said frame at the sides of said opening to moveindependently both laterally and toward and from said opening, and means'for independently adjusting said devices to stretch saidsheet evenlyover said frame opening, each of said devices comprising a pair ofmembers having ,jaws adapted to grip an edge of the sheet, a'

locking lever connected to one ofsaid members and havinga cam portionadapted to engagethe other member to force and'hold its. j aw intogripping relation with the other jaw,

and a weighted part on-.said other member adapted when said lockinglever is released to cause said jaws to open to release the edge of saidsheet.

5. A portable holder for a flexible sheet or film comprising a framehaving an opening for'the passage of light, a plurality off sheetgripping and stretching devices movably mounted on said frame at thesides of said opening, and means for independently adjusting saiddevices toward and from said opening to stretch said sheet locally andevenly over said frame opening, and means for permitting independentlateral movements of said devices during said adjustments, each of saiddevices comprising a pair of .members having jaws adapted to gripan edgeof the sheet, one of said members being movable toward and from theother, and a locking device adapted to rengage said movable member toforce and hold its j aw in gripping relation to said other jaw, andmeans adapted, when said locking device is released to ositively opensaid jaws to release the edge ot said sheet and to retain the jaws openas long as said locking device is in released position.

6. A portable holder for a fieXible image bearing sheet or filmcomprising a frame having an opening for the passage of light, aplurality of sheet gripping and stretching devices slidably mounted onsaid frame at the several sides of said opening to move independentlyboth laterally and toward and from said opening, and means forindependently adjusting said devices to stretch said sheet evenly oversaid frame opening, each of said devices comprising a pair of members, arocking connection between said members, each of said members having ajaw at one side of said connection and a locking device at the oppositeside of said connection arranged to engage said members and rock onemember to force and hold its jaw into gripping relation with said otherjaw.

7 A portable holder for a flexible photographic sheet or ilm comprisinga'frame haved to move said devices independently rela- Y tively to saidframe to apply tension to said sheet to draw itftaut and smooth oversaid frame opening,'said adjusting means comprising a screwfor eachdevice, an abutment on said frame having a slot inwhich said screw isheld from endwise movement but which permits limited lateral movementsof the screw, said screw having a threaded engagement with said grippingdevice to move the same by turning said screw.

8. A portable holder for a iexible image bearing .sheet or filmcomprising a frame having an opening for the passage of li ht,

means forming a raised bearing exten ing continuously around saidopening and on which the edge portions 'of said sheet may bear, and aplurality of independently adjustable sheet gripping and stretchingdevices movably mounted on said frame at each of the several sides ofsaid opening and adapted for attachment toA the edges of said sheet atpoints outwardly beyond said bearing, said devices being adapted toapply tension to said sheet to pull said edge portions over said bearingand stretch the sheet across said frame opening. A

9. A portable holder for a iexible image bearing sheet or filmcomprising a trame having an opening` for the passage of light, meansforming araised bearing extending contlnuously around said opening andon which the edge portions of said sheet may bear, a plurality of sheetgripping and stretching devices independently movably mounted on saidframe at the several sides of said opening, and means for providingindependent adjustments of saidy devices both laterally and toward andfrom said opening, said devices having gripping jaws adapted toreleasably engage the edges of said sheet outwardly. beyond said bearingand pull said edge portions against said bearing and stretch said sheetacross said frame opening by applylng tension to said sheet by adjustingsaid devices.

10. A portable frame for a flexible image bearing sheet or filmcomprising a frame having an opening. a rigid transparent platesupported on said frame and crossing said opening with its edgesdisposed adjacent the edges of said opening, 'a plurality of movablesheet stretchingV devices on said frame at each of the several sides ofsaid opening and ada ted for quick attachment to anddetachment rom theedges of said sheet outwardly beyond the y edges of said plate, andmeans for moving each of said devices independently away from the edgesof said opening to apply tension independently to diiierent portions ofsaid sheet and draw its edge portions against the edge corners of saidplate and stretch said ilm over said opening.

1.1. A portable frame for a `flexible image bearing' sheet or iilm,comprising a frame having an opening yfor the passage oflight, a rigidtransparentI plate supported on'said frame and crossing said openingwith its z edges disposed adjacent the edgesof said opening, a pluralityof movable sheet stretching devices on said frame at each of the severalsides of said opening and adapted for attachment to the edges of saidsheet outwardly beyondthe edges of said plate, means A for moving saiddevices independently to apply tension independently to differentportions of said sheet and draw its edge portions against the edgecorners of said plate and stretch said film over said opening, and in--i/ng therein, a rigid transparent plate crossing said opening andhaving its edges disposed adjacent the edges of said opening, adjustabledevices on said frame each adapted to engage an edge of said plate toadjustably position the same in relation to said opening, a plurality ofadjustable devices on said frame at each of the several sides of saidopening adapted to engage the edges of a sheet or film arranged oversaid plate, and

means for independently applying tension to so said last mentioneddevices to draw said sheet taut and adjustably position the same oversaid opening and said plate.-

13. A portable holder of the character described comprising a framehaving an opena5 .ing therein, a rigid transparent plate arranged oversaid opening and having its edges .disposed adjacent the edges of saidopening, a plurality of adjusting devices on said frame at the sides ofsaid opening adapted to adjustably secure said plate on said frame inpredetermined location over said frame opening, each of said devicescomprising a jaw adapted to move towards and from said plate and toengage an edge thereof, a

guide for said,` jaw, a bearing in which said guide is arranged to havea limited rotating movement in the planeof.i said plate, and means foractuating said jaw.

14. A portable holder of the character de- 10D scribed comprising aframe having an opening therein, a rigid transparent plate arranged oversaid opening and having its edges disposed adjacent the edges of -saidopening, a plurality of adjusting deviceson said frame at the sides ofsaid opening adapt-l ed to adjustably secure said plate on said frame inpredetermined location over said frame opening, each of said devicescomprising aj aw adapted to move towards and from said plate and toengage an edge thereof, a guide for said jaw, a bearingin which saidguide is arranged to have a limited rotating movement in the plane ofsaid plate, an adjusting screw in said guidewarranged to ro-,ll

tate without endwise movement relatively thereto and engaging athreadedhole in said j aw for moving the same to and from an edge of said plate.

15. The combination of a portable holder 12o for a flexible imagebearing sheet or film comprising a frame having' an opening, a pluralityof sheet securing devices movably` mounted on said frame at theY sidesof said opening, adjusting means adapted to move port for said holder,and means for detach- Aai ably securing the holder on the support andadjusting the holder relatively to the support to place said registeredimage in predetermined location.

16. The combination of a 4portable holder for a iexible image bearingsheet or film comprising aframe having an opening, a plurality of sheetsecuringv devices movably mounted on said frame at the sides of saidopening, adjusting means adapted to move said devices relatively to saidframe and apply tension to said sheet to draw the same taut and smoothover said opening and place said image into predetermined register, asupport for said holder comprising two substantially flat superposedmembers having central apertures which register substantially with eachother and with said frame opening, means for detachably securing saidholder on one of said members,means for detachably securing saidmember'on the other member, and means for adjusting one 4of said membersrelatively to said other member to place said registered image inpredetermined location.

17. The combination of a portable holder for a flexible image bearingsheet or lm comprising a frame having an opening, a plurality of sheetsecuring devices movably mounted on said frame at the sides of saidopening, adjusting means adapted to move said devices relatively to saidframe and apply tension to said sheet to draw the same taut and smoothover said opening and place said image into predetermined register, asupport for said holder, and means for detachably securing the holder onthe support and adjusting the holder relatively to the support to placesaid 'registered image in predetermined location, said support beingadapted to be secured in predetermined location on a photographicprinting apparatus or in a like location on an image positioning or thelike device.

18. The combination of a portable holder for a iiexible yimage bearingsheet or ilm comprising a frame having an opening, a plurality of sheetsecuring devices movably mounted on`said frame at the sides of saidopening, adjusting means adapted to move said devices relatively to saidframe and apply tension to said sheet to draw the same taut and smoothover said opening, a support for said holder on which the same isadapted to be detachably secured, said support being adapted to besecured in predetermined location on an image positioning or the likedevice so that by adjusting said securing devices on said holder saidsheet may be stretched to place said image into predetermined registerby means of said image positioning device.

19. The combination of a' portable holder for a iexible image bearingsheet or film comprising a frame having an opening, a plurality of sheetsecuring devices movably mounted on said trame at the sides or" said.l

opening, adjusting means adapted to move said devices relatively to saidframe and apply tension to said sheet to draw the same taut and smoothover said opening, a support for said holder on which the Same isadapted to be detachably secured, said support being adapted to besecured in predetermined location on an image positioning or the likedevice so that by adjusting said securing devices on said holder saidsheet may be j stretched to place said image into predetermined registerby means of said image positioning device, said support being furtheradapted to be removed from said positioning device and secured in acorresponding position on a. photographic printing apparatus, andadjusting means on said support adapted to move said registered image onsaid holder into register with a predetermined image position on saidapparatus.

20. A portable holder for a flexible sheet or film, comprising a framehaving an opening across which said sheet extends, a plurality ofindividual and independently movable sheet gripping and stretchingdevices mounted on said frame at the several sides of said opening forgripping the corresponding edges of said sheet, and means forindependently adjusting each of said devices away from said opening tostretch the sheet evenly thereover, means permitting individual lateraladjustments of said devices for effecting lateral adjustment of saidsheet, and means on said frame engaging and retaining said devicesthereon and which, when lateral adjustments or" one or more devices at aside of said sheet are made permits other devices at said side to movewith said sheet and relatively to said frame during such adjustments andwithout upsetting the :first mentioned adjustments of said devices.

21. A portable holder for a flexible sheet or film, comprising a framehaving an opening across which said sheet extends, a plurality ofindividual and independently movable sheet gripping and stretchingdevices mounted on said frame at the several sides of said opening forgripping the correspond'- ing edges ofsaid sheet, and means forindependently adjusting each of said devices away from said opening tostretch the sheet evenly thereover, and means on said frame engaging andretaining said devices thereon and which, when said devices at one edgeof said sheet are adjusted to stretch said sheet in one direction,permits the devices at those edges of the sheet which extend in thatdirection, to move laterally with said sheet and relatively to saidframe without upsetting adjustments of said last mentioned devices madefor stretching said sheet in a crosswise direction. v

WILLIAM C. HUEBNER.

